These are terrain-alterable overlays for use with VASL.  Place the following
files in a subdirectory named "overlays" in the boards directory:

ovr1
ovr2
ovr3
ovr4
ovr5
ovr6
ovrB
ovrDX
ovrG
ovrHI
ovrM
ovrO
ovrOG
ovrOW
ovrP
ovrRP
ovrRR
ovrST
ovrWD
ovrX
